Measuring scoops for granular products, which are placed in packages for user convenience in volumetric measuring, are old in the art. Such scoops are found particularly with granular detergent and coffee products, where volumetric measuring is beneficial to obtaining reproducible results. Measuring scoops typically are molded of plastic and have a measuring portion connected to a handle portion. The measuring portion typically has a cylindrical or rectangular body surrounding an open cavity of the same shape.
Scoops are designed to be placed in the top of a container in one of two ways. In a first method, the container is filled with granular product and then a small scoop is placed on top of the product before the container lid is installed. In a second method, the container is inverted with top down. The scoop is then placed in the container. The scoop is then covered by filling a granular product around it. The container bottom is thereafter installed. When the container is reinverted, the scoop is at the top end of the container where the lid will be opened by the consumer. The second method is preferable where the scoop is large relative to the size of the container or where the container is shaped to have a headspace which will not accommodate dropping in a scoop on top of the product.
In the coffee business, containers for ground coffee have traditionally been vacuum packed or pressure packed metal cans. Such cans are cylindrical and have ends seamed onto both ends. This design lends itself well to the second method of scoop placement. However, more recently, molded plastic bottles are being considered for ground coffee. The plastic bottles are designed to look like cans. The key difference is that a bottle has only one open end. It is filled and emptied through the same open end. Thus, the second method of placing a measuring scoop is not available without some method of causing a scoop placed in the bottle bottom to later rise to the top of the bottle.
A Discover magazine article discusses size separation within a can of mixed nuts. According to the article, "shaking a can of mixed nuts sets up a nut current in the whole can that looks like the convective roll of boiling water." When small glass beads are placed in a jar with one large glass bead, shaking the container sets up a current flow within the container such that beads against the container wall move downward, while beads that are one or two bead diameters inside the container wall move upward. The large bead is lifted to the surface of the beads where it stays while the smaller beads move radially to the surface of the container and then downward. Shaking is believed to be the driving force for the currents within the beads. The author believes that wall friction is the key to size separation, because in a nearly frictionless walled container, no current or flow of beads was initiated. In the case of canned nuts, size-based separation is an undesirable consequence.
It is an object of the present invention to apply the mixed nut size separation phenomenon to cause a submerged measuring scoop to rise through granular material in a container to the container headspace, where the scoop is available to be used by a consumer to remove measured volumes of granular material.
It is a further object of the present invention to provide a measuring scoop which is designed to minimize the time or effort required to lift a scoop from the bottom of a container to the headspace of the container when the container is filled with a granular product.